Project Summary Impaired social functioning during the preschool years is common feature of many of the neurodevelopmental disorders. Whereas most preschool children are forming first friendships and progressing from parallel to complex and coordinated dramatic play, children with neurodevelopmental disorders often lack the inhibitory control, attention focus, emotion regulation, and empathic social responsiveness needed for effective social collaboration. Preschool social impairment predicts significant difficulties in later learning, peer relations, and social-emotional functioning, making early, preventive intervention a priority. Three recent studies have demonstrated that classroom-level interventions designed to enhance the social-emotional learning and self- regulation skills of preschool children can improve social collaboration skills and, concurrently, strengthen neurocognitive executive functioning as it develops (Bierman, Nix, Greenberg, Domitrovich &Blair, in press;Diamond, Barnett, Thomas &Munro, 2007;Riggs, Greenberg, Kusche &Pentz, 2006). These intervention techniques may hold considerable promise for preventing or reducing the difficulties experienced by children with neurocognitive disorders, if delivered during the preschool years in an intensive format that provides extensive support for skill development. Based upon a social-cognitive neuroscience developmental model, the proposed study will develop and refine an intervention called Patterned and Intentional Play Sequence [PIPS] Coaching. This new intervention will utilize small group social experiences, structured around activities and games that are organized developmentally to elicit and support increasingly complex social collaboration, with therapist "coaching" to support social responsively and self-regulation skills. We will evaluate the efficacy of this intervention in a rigorous, randomized-controlled, phase 1 clinical trial involving 128 4-year-old children with emerging ADHD. Multi-method measures (including direct child assessments, observations, and teacher and parent ratings) will assess intervention impact on proximal outcomes (preschool social competencies, EF skills, learning engagement) and on distal outcomes (kindergarten school adjustment and reduced ADHD symptomatology).